How are the Dolphins doing it? Here are five under-the-radar reasons Miami is undefeated:

Clay

Tight end Charles Clay: There were questions this preseason of who would step up in the absence of former starting tight end Dustin Keller. Clay has done a good job of filling Keller’s role in the first two weeks of the regular season. Clay is tied for second on the team with 10 receptions and is second in yards with 163. He had a big game Sunday against Indianapolis with five catches for 109 yards. With much of the focus on receivers Mike Wallace and Brian Hartline, Clay has been able to do some damage underneath to keep the chains moving.

Third-down defense: Miami’s defense is getting off the field when it matters most on third downs. Opponents are being held to a 27.6-percent conversion rate on third down. By comparison, Miami’s offense is converting on 46.7 percent of its third downs. That’s a huge difference, especially in close games. The Dolphins have been good so far at creating third-and-long situations and getting to the quarterback on obviously passing downs. Miami has nine sacks and four interceptions in two games.

Sturgis

Kicker Caleb Sturgis: Sturgis is quietly proving to be a solid draft pick. The rookie fifth-rounder is a perfect 5 for 5 on field goals, including a big 54-yard kick before halftime that tied the score against the Colts. Sturgis also is perfect on four extra points and consistently produces touchbacks. He’s quickly made Dolphins fans forget about former kicker Dan Carpenter.

Defensive end Derrick Shelby: In limited playing time, Shelby has contributed a sack in each of the first two games. The backup defensive end started to come on strong in the preseason. He’s earned playing time as the fourth defensive before Pro Bowler Cameron Wake, starter Olivier Vernon and rookie first-round pick Dion Jordan.

The Dolphins are getting contributions from both their star players and under-the-radar contributors. It will be key for Miami to continue this trend throughout the season.